orthoimage: The orthoimagery is a four-band, 16-bit unsigned GeoTIFF file. The orthoimagery has a GSD of 0.24 m per pixel, and the "No Data" value is set to 256. Variable sky conditions during the photogrammetry survey resulted in some illumination anomalies in the southern part of the study area.
Wolken, G.J., and Wikstroem Jones, Katreen, 2019, Photogrammetry-derived digital surface model and orthoimagery of areas near the Dalton Highway, Yukon River Crossing, Alaska: Raw Data File RDF 2019-4, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.Online Links:
This is a raster data set.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest .00000001
Ordinates (y-coordinates) are specified to the nearest .00000001
Planar coordinates are specified in Meters
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is GRS 80.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257222101000025.
These data products were funded by the Alaska Department of Transportation & Public Facilities, and Alaska Department of Natural Resources, Division of Geological & Geophysical Surveys. We thank Clearwater Air for their aviation expertise and contribution to these data products.
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The data release is one of a series of Alaska Division of Geological & Geophysical Surveys (DGGS) publications to present elevation data over Yukon River Crossing in support of landslide hazard mapping.
The DSM and orthoimagery have been visually inspected for data errors such as pits, border artifacts, and shifting. The end-user should be aware that pits and peaks are present in areas of some small water bodies, such as lakes and ponds, and that DSM data have not been hydro-flattened in these areas.
The horizontal accuracy was assessed by comparing the locations of six GNSS-derived control points with their locations in the orthoimagery. The initial mean offset (residual) was +1.35 m in the X-direction and -0.03 m in the Y-direction, with a standard deviation of 0.47 m (0.65 m, Y-direction) and a mean-absolute-error (MAE) of 1.35 m (0.46 m, Y-direction). A horizontal transformation of -1.35 m in X-direction was applied because horizontal offset was identified above the pixel scale of the DEM (i.e., 0.47 m GSD). The final horizontal accuracies were based on the same control points as checkpoints and are described in table 1 of the accompanying report. > Check Point,Horizontal Offset X (m),Horizontal Offset Y (m),Easting (X),Northing (Y),Elevation (m) > YK-01,0.64,-1.16,385213.56,7303075.69,571.24 > YK-03,0.29,0.74,376208.41,7309124.78,95.28 > YK-04,-0.66,0.53,370524.83,7315054.63,160.34 > YK-05,0.69,-0.22,371052.7,7314408.97,152.61 > YK-06,-0.12,-0.11,374073.81,7311526.54,105.19 > YK-07,0.84,0,375527.33,7310228.21,96.83 > Mean,0.28,-0.04 > Std. Dev,0.58,0.67 > Range,1.5,1.9 > MAE,0.54,0.46
The aerial photographic survey resulted in approximately 60 percent side lap and 80 percent end lap coverage, with an above ground-level flying height of 1,100-2,000 m, which resulted in 4,922 photos with 0.24 m ground sample distance (GSD). The total area surveyed was approximately 360 km2. This data release is complete.
To evaluate data consistency, ground control checkpoints were collected (September 21, 2016) as rapid-static occupations (15 min) with a Trimble R8 GNSS receiver. A Trimble R7 GNSS receiver with Zephyr-2 antenna was deployed near the center of the study area and was used as horizontal and vertical control for checkpoint baseline corrections.
Are there legal restrictions on access or use of the data?
- Access_Constraints:
- This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
- Use_Constraints:
- Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
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RDF 2019-4
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
| Data format: | orthoimage |
|---|---|
| Network links: |
<http://doi.org/10.14509/30183> |
(907)451-5020 (voice)
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